MM AL-FAHM, Israel, Sept. 14 — Despite President Bush's request that Prime Minister Ariel Sharon hold peace talks soon, Mr. Sharon decided today that he was in no hurry to ease the Palestinians' political predicament in the wake of Tuesday's terror attack in the United States, and he canceled talks planned for Sunday without suggesting a new date.

Images of some Palestinians celebrating the attacks on the United States on Tuesday have thrown Yasir Arafat, the president of the Palestinian Authority, on the defensive, Mr. Sharon believes, a government official privy to his thinking said.

"There's no more playing around, this is a new world now," said the official. Referring to Mr. Arafat, he added, "There's no reason just to have a meeting that lets him off the hook."

Mr. Sharon also had a political problem his own. Conservative Israeli politicians, including some in his own cabinet, vehemently and publicly opposed following through with the meeting, which was to have been held between Mr. Arafat and Foreign Minister Shimon Peres. Mr. Sharon is very popular here in this Israeli Arab town in the rocky hills northeast of Tel Avi, but he is wary of being challenged from the right by Benjamin Netanyahu, the former prime minister.

For its part, the United States is eager for a productive meeting in order to build support among Arab countries for an anti-terrorism coalition, and Secretary of State Colin L. Powell was clearly disappointed by Mr. Sharon's decision. But the Israeli official said that Mr. Arafat had taken no steps to demonstrate he was serious about fighting terror.

"He has to take action," the official said.

Palestinian officials expressed surprise today when informed by reporters that the meeting, which had been rescheduled many times already, was off again. Mr. Peres told Israeli television that he would continue pushing Mr. Sharon to permit the meeting.

Another, not incidental, effect of canceling the meeting was to call further attention to Palestinian celebrations after the attacks in New York and near Washington. Despite two days of damage control, during which Mr. Arafat and other leaders have condemned the attacks and ordinary Palestinians have rallied in solidarity with the United States, the Palestinian Authority continued today to try to squelch reports of celebrations. In fact, it shouldered the additional burden of trying to squelch reports of squelching reports.

Most West Bank towns were quiet on Tuesday after the attacks, but Nablus was an exception, and journalists who tried to report on a rally there in support of the terrorist attacks said that Palestinian gunmen threatened them. The Associated Press has not released footage of the rally because its cameraman on the scene felt that doing so would endanger his life. The Foreign Press Association in Jerusalem has formally protested to the Palestinian Authority "over the harassment of journalists by the Palestinian Authority" and "direct threats made against local videographers by local militia members."

As Palestinian officials continued denying today that any such threats were made, Israelis officials were busy directing reporters' attention to reports about Palestinian intimidation of the news media. Today, the Agence France-Presse news agency reported from Gaza that five journalists were briefly detained and that their equipment was seized by the Palestinian police after they filmed a demonstration, by the radical group Hamas, in memory of an Israeli Arab suicide bomber who killed himself and three Israelis on Sunday.

That suicide bomber — the first Israeli Arab to commit such an attack — was not mentioned from the stage tonight at a mass gathering of Israeli Arabs here. Tens of thousands of Israeli Arabs turned out for the sixth annual rally held by the more radical branch of Israel's growing Islamic movement.

The rally's stated theme was the protection of the Al Aqsa Mosque in Jerusalem, one of Islam's holiest sites, and its subtext was the growing unrest of Israel's Arab minority. The suicide bombing on Sunday and a recent bombing attempt by Israeli Arab youths have heightened fears among Israeli Jews of a Palestinian fifth column within their borders.

Timed to dominate the evening news programs, the rally, in a hilltop soccer stadium, was part carnival and part religious service, but it was thoroughly political. Vendors sold hot dogs, Mickey Mouse balloons and cassette tapes offering instructions on participating in the intifada, and a boy band performed a song about rebellion, not romance.

Ra'ed Salah, the leader of the Islamic movement, declared his opposition to terror "in all its shapes." He said he opposed killing civilians "all over the world — in Palestine, in Iraq, in America."

Mr. Salah had a particular message for President Bush. If the American president wanted to achieve piece and security, Mr. Salah said, "the only solution is for Bush to convert to Islam." He added that "there is no war between Islam and America."

The relatives of young men killed by the Israeli police during the past year's conflict sat in the front row. Adnan Yazbak of Nazareth sat behind a picture of his nephew, Wusam Yazbak, shot dead, his uncle said, while fleeing after a demonstration.

"We have to remember that people being killed have kids and families, like us," Mr. Yazbak said with tears in his eyes, adding that he was horrified by the attack on the United States. "Believe me, it is from the heart, it is not words."

The grand mufti of Jerusalem, who is appointed by Mr. Arafat and is the senior spiritual leader of the Palestinians, was supposed to attend the rally, but he was picked up by the Israeli police today after prayers. The mufti, Sheik Ikrima Sabri, said that he was held for three hours and accused of incitement before being released.

In other skirmishing today, one Palestinian was shot dead in Gaza by Israeli troops, who said they were responding to an attack by Palestinians throwing stones and hand grenades. Also, two Israeli border policemen were injured by a hand grenade thrown near the Erez crossing point on the Gaza border — one potential site for the meeting that was canceled.